The present invention relates to paving equipment. More particularly, the present invention relates to a swing conveyor used in the transfer of paving material from the haulage vehicle to the paving vehicle.
In paving large surfaces, for example roadways and parking lots, paving vehicles (also referred to as xe2x80x9cpaversxe2x80x9d), are typically utilized to lay a smooth mat of material in continuous strips between ten and twenty feet in width. It is preferred that the paver maintain a continuous forward advance during the laying of each individual strip. Any stopping during the process may result in uneven material application or other imperfections in the laid mat.
Pavers generally include a large hopper for holding the paving material, however, in most applications, the hopper is unable to hold sufficient material to lay a complete strip. To avoid stopping of the paver to reload the hopper, various methods have been develop to provide a continuous supply of material to the paver as the paver maintains a forward advance.
One method of supplying the paver is known as the windrow material deposit method. In this method, a truck proceeds in front of the paver and dumps a xe2x80x9cwindrowxe2x80x9d deposit of material in the path of the paver. A windrow elevating machine attached to the front of the paver scoops up the deposited material as the paver advances forward and conveys the material to the paver hopper. While this method has had some success, placing of the material on the ground surface can result in excessive cooling of the material which may adversely affect the paving operation.
Another method of supplying the paver is by directly dumping material from a truck into the hopper. A truck loaded with paving material is positioned in front of the paver with the paver hopper extending under the truck""s dump bed. The truck and paver move forward in unison and material is dumped from the truck directly into the hopper as needed to maintain a continuous supply of material in the hopper. However, the height of the truck bed and the lack of a large overhang, generally prevent the truck from completely filling the hopper. Without a full hopper, the paver can operate only operate for a limited time, for example, approximately thirty seconds, without refilling from the truck. Therefore, truck changeover, i.e. the replacing of an empty fill truck with a new, full fill truck, must be accomplished very quickly to allow continuous paver advancement. Such quick changeovers are often difficult, if not impossible, to accomplish.
To increase change over time, material conveying machines have been employed between the material truck and the paver hopper. The material conveying machines have a low collection head which allows easier transfer of material from the truck bed. The material is conveyed from the collection head to a large capacity hopper, often the same capacity as the truck bed. An elevated conveyor transfers the material from the large capacity hopper to the paver hopper. Since the conveyor is elevated, the paver hopper can be completely filled. Additionally, the large capacity hopper allows a continuous supply of material even during a truck change over. An example material conveying machine is the Blaw Knox MC-330 material conveyor.
In some paving operations, for example, in tight confines, it is difficult to pave with the truck and material conveying machine directly in front of the paver. It is desirable to provide a second conveyor attached to the rear of the material conveying machine which is rotatable approximately 180xc2x0, thereby allowing side delivery to the paver hopper. The second conveyor is preferably rotatable about a vertical axis extending through the discharge area of the material conveying machine conveyor such that the conveyors remain aligned and material can be received over the full range of rotation.
It is also preferable that the second conveyor is positioned on a platform pivotally interconnected with the material conveying machine and supported by an independent wheel assembly. As such, the second conveyor is independently supported, i.e., the weight of the second conveyor is not carried by the material conveying machine. Adding additional weight to a previously balanced conveying machine may result in an undesireble weight imbalance for the conveying machine. Additionally, the pivotal interconnection with the conveying machine allows the second conveyor assembly to vertically adjust as it travels over surface irregularities.